Heel-releasing device for safety ski bindings



May 6, 1969 HEEL-RELEASING DEVICE FOR SAFETY SKI BINDINGS Filed May 2,1967 E. HEcKl. y 3,442,525

United States Patent O U.S. Cl. 280-11.35 3 Claims ABSTRACT OF THEDISCLOSURE The sole holder is secured to a pivoted lever, which ispivoted on a transverse pivot, which is fixed relative to the ski. Thepivoted lever is slidably mounted on -the transverse pivot by a guideslot. A spring force in a forwardly and downwardly inclined directionacts between the pivoted lever and the ski. The sole holder is mountedon -the pivoted lever for an upward pivotal movement. A detent devicewhich is disengaged in response to an excessive tension is providedbetween the sole holder and the pivoted lever.

Heel-releasing devices for safety ski bindings, so-called step-inbindings, are known, in which devices the sole holder is secured to alonger pivoted lever, which has a detent socket engaged by a springloaded detent pin. Just as other known designs, this knownheel-releasing device has the disadvantage that the foot is very rigidlysecured .to the ski so that fatigue is soon experienced. Besides, theknown heel-releasing device does not force the foot forwardly againstthe toe iron of the ski binding and at the same time downwardly againstthe ski.

In a heel-releasing device for safety ski bindings, in which device thesole holder is secured to a pivoted lever, which is pivoted on atransverse pivot, which is fixed relative to the ski, thesedisadvantages are avoided `according to the invention in that thepivoted lever is slidably mounted on the transverse pivot by a guideslot, a spring force in a forwardly and downwardly inclined directionacts between the pivoted lever and the ski, the sole holder is mountedon the pivoted lever for an upward pivotal movement, and a detent devicewhich is disengaged in response to an excessive tension is providedbetween the sole holder and Ithe pivoted lever. The slidable mounting ofthe pivoted lever on the transverse pivot and the spring force in aforwardly and downwardly inclined direction ensure that theheel-releasing device resiliently urges the foot forwardly against thetoe iron. The spring acting in a forward and downward direction ensuresat the same time that the foot can lift from the ski within certainlimits against the force of the spring and can carry the pivoted leverand the sole holder along in this movement so that the above-mentionedfatigue is avoided. Only an excessively high tension moment during afall will release the detent between the sole holder and the pivotedlever so that the sole holder performs an upward pivotal movement andthe foot can free itself from the heel-releasing device without anydiiculty because the foot is perfectly freed from the sole holder andneed not slip past an only slightly displaced sole holder, as is thecase with various known heel-releasing devices.

In a development of the invention, a bolt is pivoted to a base plate,which is fixed to the ski, said bolt extends through an oversize openingin the pivoted lever and a coiled compression spring bears at one end ofa spring abutment plate at the free end of the bolt and at the other endon the pivoted lever so that the spring force acting in a forward anddownward direction is produced. Besides,

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the detent device between the pivoted lever and the sole holder maycomprise a detent lever, which is pivoted to the pivoted member andbears by the release spring on the pivoted lever and is provided at itsfree end with an actuating means for an arbitrary opening of theheelreleasing device.

The invention will be explained more fully hereinafter with reference tothe drawing, which shows an embodiment by way of example.

FIG. 1 is a vertical longitudinal sectional view show- Y ing aheel-releasing device according to the invention and FIG. 2 is a sideelevation showing the releasing device of FIG. 1 in the releasedposition.

A base plate 3 is secured by screws 2 to a ski 1 and has on its sidestwo upright lugs 5. A pin 6 extending transversely to the longitudinaldirection of the ski is mounted in the two lugs. A pivoted lever 7 ismounted on the pin 6. The pin is received by a slot 8 of the pivotedlever 7 so that the latter is displaceable in the longitudinal directionof the ski. By means of another pin 10, which extends also transverselyto the longitudinal direction of the ski, a bolt 9 is pivotallysuspended between the two fixing lugs 5. The bolt 9 has a `bearing eye,which receives the pin 10. At its free end, the bol-t 9 is provided withscrew threads. The bolt 9 extends through an oversize opening 11 of thepivoted lever 7 and is threaded into an adjustable spring abutment plate12. A spring 13 bears at one end on the spring abutment plate 12 and atthe other end on the pivoted lever 7. Owing to the inclina-tion of thebolt 9 and of the spring 13, the pivoted lever is resiliently urged in adownward direction and pushed forwardly toward the tip of the ski.

A sole holder 14 is pivoted to the pivoted lever 7 with two lugs 15,which embrace the pivoted lever 7 and are connected to it by the pin 16.To hold the sole holder in its normal position, a detent device isprovided between the sole holder 14 and the pivoted lever 7. In theexample shown, the detent device consists of a detent lever 4, lwhich ispivoted by a pin 18 in an aperture 17 of the pivoted lever 7. Under theaction of :the release spring 19, the detent lever 4 is urged againstthe sole holder. The detent lever 4 has a nose 20, which engages amating detent recess 21 of the sole holder. To enable an arbitraryopening of the binding, the detent lever 4 is prolonged and providedwith a conical recess 22. To open the binding, the ski stick is insertedinto the recess 22 and used to depress the lever 4 against the force ofthe spring 19 so that the nose is disengaged from the recess 21. Theheel can now be lifted so that the sole holder is pivotally movedrelative to the pivoted lever 7 and releases the heel.

The sole holder 14 has a step-in pedal 23, which is engaged by the heelas it steps into the binding so that the sole holder is depressed untilthe nose 20 snaps back into the recess 21. The sole holder is providedat its forward end with teeth 24, against which a retaining member 25 isforced, which is formed with mating teeth. The connection lbetween theretaining member 25 and the sole holder In response to excessive forcesat right angles to the surface of the ski, the pivoted lever 7 willperform a predetermined upward pivotal movement about the pin 6 againstthe action of the spring 13. The sole holder, which is held by thedetent on the pivoted lever, will follow the movement of the latter.When the force reaches the value to which the detent has been preset byan adjustment of a predetermined initial stress of the spring 19, thedetent device will be released to permit of a pivotal movement of thesole holder relative to the pivoted lever 3 so that the boot is freed.If the force acting at right angles to the surface of the ski is not solarge, the spring 13 will return the boot to the surface of the ski.

It has already been described that a special advantage of theheel-releasing device according to the invention resides in that it canfollow small upward movements of the' heel without causing a release ofthe foot. This elastic connection between the boot and the ski precludesin a high degree of fatigue of the foot and the consequent pain on thesole of the foot. Another advantage resides in that the inclinedorientation of the spring 13 ensures a resilient cushioning of movementsat right angles to the ski as well as a forward pressure on the foot.

As the forwardly and downwardly acting spring and the releasing springare separate, the sole holder can perform a large pivotal movementrelative to the pivoted lever upon a release so that the boot isentirely freed and the heel does not merely slip out of the sole holder,as is the case with many known bindings. The latter operation may causedamage to the heel after prolonged use. A further advantage resides inthat the release spring may be relatively weak so that a small openingwork performed on the detent lever will be suhicient when the userdesires to step out of the binding. In spite of the relatively weakdetent spring, the arrangement of the interengaging surfaces and of thepivotal axes of the detent lever and sole holder may be selected so thatthe detent will not be released unless relatively large forces areeffective.

What is claimed is:

1. Heel release device for safety ski binding comprising a leverpivotally mounted to a ski about a pivot axis extending transversely tothe ski, a sole holder pivoted to said lever, spring means biasing saidlever to counteract upward and rearward movement thereof, said leverdelining a slot extending normal to and through which said pivot axispasses to enable movement of said lever in a fore and aft direction withreference to the ski, detent means releasably holding said sole holderand said lever rigidly engaged under normal operating conditions andupon the occurrence of an excessively high pulling force releasing toenable said sole holder to pivot relative to said lever.

2. Heel release device according to claim 1 wherein said detent meansincludes a detent lever pivoted at one end to said pivoted member whichis resiliently urged by a spring to a forward position at which itengages with said sole holder, said lever provided at its free end withan actuating means to effect an arbitrary opening of the heel releasedevice.

3. A heel-releasing device according to claim 1, characterized in that abolt is pivoted to a base plate, which is fixed to the ski, said boltextends through an oversize opening in the pivoted lever and a coiledcompression spring bears at one end on a spring abutment plate at thefree end of the bolt and at the other end on the pivoted lever so thatthe spring force counteracting upward and rearward movement is produced.

References Cited UNITED STATES PATENTS 3,278,195 l0/ 1966 Salomon280-l1.35 3,317,217 5/1967 Poiger 280-l1.35 3,366,394 1/1968 Shimizu280-1 1.35

BENJAMIN HERSH, Primary Examiner. L. DANIEL MORRIS, IR., AssistantExaminer.

